Why measure CO2 in buildings?
The level of carbon dioxide in the air can affect the human body. The recommended indoor concentration of CO₂ is around 800 ppm. Any lower (e.g. 600 ppm) and the room is overventilated, which is unnecessary and potentially costly.
The hygienic limit is around 5,000 ppm. At higher CO₂ concentrations (around 15,000 ppm), people can experience shortness of breath and an increased heart rate. Concentrations of 20,000 - 80,000 ppm can cause convulsions, immediate paralysis and, in a worst-case scenario, death.
How does it work?
The CO₂ concentration in a room varies depending on the number of people in it. Generally, an empty room has a concentration of about 400 ppm (normal outdoor concentration). The CO₂ concentration in the room will increase for each person added.
That is why a small Demand Controlled Ventilation system could be a good idea. This system has a sensor that measures the CO₂ value and sends a signal to a ventilator or a VAV-device, that then changes the level of ventilation required in the room. The system also has variable dampers that are commonly used to regulate the air flow through the sensor.
In essence, a minor ventilation system is an intelligent sensor or analyzer that adjusts one fan in the room in which it is located. This fan then regulates the air flow.
This application saves a lot of money in the form of energy savings: room fans will only operate for as long as they need to, based on the level of CO₂ in the environment. This reduced use of energy is also good for the environment and a good way to conserve Earth’s resources. Also, the indoor air quality improves, due to a reduction in the number of viruses and bacteria. Ventilating a room also reduces the number of particles occurring indoors.
Tests on buildings where Demand Controlled Ventilation is used show that energy costs are reduced by about 30%, which can lead to a return on investment in about 1 year.
- Energy savings
- Positive environmental impact
- Healthy indoor air quality